The postdoctoral research training program in endocrinology and diabetes at the Massachusetts General Hospital (MGH) provides intensive research experience in basic and clinical investigation, complemented by didactic training in basic sciences pertinent to endocrinology and diabetes. The trainees are primarily M.D./Ph.D.'s and Ph.D.'s selected from a large applicant pool on the basis of prior academic and/or research achievement and evidence of commitment to a career in biomedical investigation. The program director, Joseph Avruch, is assisted by a committee of seven experienced scientists including Joel Habener, Henry Kronenberg, William Crowley, Robert Neer, Anne Klibanski, Andrew Arnold and John Potts. Trainees are supervised by a primary faculty mentor from this group, but also interact extensively with junior faculty who serve as secondary mentors. The training faculty overall consists of 40 scientists with interests which range across the subdisciplines of endocrinology. A program of didactic sessions complements the research training. The training period is generally two to three years, but frequently includes additional years at a junior faculty level. Productivity of past trainees has been extremely high, as judged by the number and quality of trainee publications. Trainee graduates (186 overall since 1984, with 45 supported by this grant) have achieved stable and productive careers in academic medicine and biomedical investigation at a frequency of approximately 75%. Moreover, approximately 50% of trainees achieve independent research support (RO1 equivalent) within 6 to 7 years after leaving the program. Facilities at the MGH include an active clinical research center, access to a large base of endocrine and diabetes patients, and an extraordinary program of basic science investigation which includes studies of gene regulation, protein structural analysis, transmembrane signaling mechanisms, as well as many other areas.